HV_REGULATOR_WITH_FOLDBACK_CURRENT_LIMIT

Published:2009/6/24 1:46:00 Author:May | From:SeekIC

The output current issensed across R8, This is delivered to the current-limit arrtplifier through R7, across which the foldback potential is developed by R6 with a threshold determined by D4. The values given limit the peak power below 20 W and shut off the pass transistors when the voltage across them exceeds 310 V. With unregulated input voltages above this value, start-up is initiated solely by the current through R5. Q4 is added to provide some control on current before A2 has time to react.The circuit is stable with an output capacitor greater than about 2 μF. Spurious oscillations in current limit are suppressed by C2 and R4, while a strange, latch-mode oscillation coming out of current limit is killed with C1 and R1.



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